Is this boat too heavy?

bowman316

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Oct 21, 2008
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I have a 16 ft fiberglass runabout with a 70 HP evinrude on it. The boat is a 79 with a 81 engine on it. The make is a thompson.
The boat and trailer together weigh about 3,000 lbs. I know this because i had it weighed at the dump.

I suspect that my floor is rotten, or the floatation foam is holding water.

It is a single axle trailer, i guess it weight between 750 - 1,000 lbs. So the boat alone weights about 2,000 or more lbs. Does this sound high?

I did have to replace a rotten transom, but never touched the floor.
 

tashasdaddy

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Re: Is this boat too heavy?

time to investigate. drill some test holes with a hole saw and power drill, save the plugs, then take a piece of pvc cut notches in one end, like teeth, and twist down into the foam then push out the core. you will know immediately.
 

bowman316

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Re: Is this boat too heavy?

there is a soft spot in the back, in front of the splash well.
I might just remove that section and replace it with plywood.
Looks are not my biggest concern
 

fishrdan

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Jan 25, 2008
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Re: Is this boat too heavy?

With that weight I would suspect a lot of water in the boat, soaked foam, rot...

I scaled my 73 16.5' SeaSwirl, trailer and fishing gear,,, 3200#. My boat had a Mercruiser 140HP which weighed 7-800# so the power plant was heavier on my rig. When I ripped up the decks I found soaked foam and rot. From the small amount of material (fiberglass, wood, soaked foam) I removed from the boat I guesstimate I was hauling around an extra 5-600# of water :eek:

Time to do some core samples as TD suggests.

Under the impression I was going to rebuild my boat (which I didn't) I did the core sample with an 8" circular saw:rolleyes:,,, but a 2" hole saw would have worked better:D
 

bowman316

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Re: Is this boat too heavy?

so dan, did you rip out the floor and put in new stringers and everything?
or just clear out the foam and put new foam in?

I kinda wana make storage comparments under my floor. Trap door like compartments
 

steelespike

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Apr 26, 2002
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Re: Is this boat too heavy?

If the stringers turn out to be rotted your bottom is more than likely distorted.
Does the boat seem to lay down too much unable to trim the bow up?
 

bowman316

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Re: Is this boat too heavy?

I don't have power trim, But the bow does ride a little low, it is cerntantly not high.
I will try tilting the motor more away from the transom, and seeing it the bow raises.

I would not say the bow is dangerously low in the water.
 

fishrdan

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Re: Is this boat too heavy?

so dan, did you rip out the floor and put in new stringers and everything?

Naw,,, I ripped every last piece of hardware off the boat and hauled the remains it to the land fill where they crushed it and gave it a proper burial :D Even though I had the boat for 10 years, I didn't like how the tri-hull rode and wasn't going to invest the time, $$$ and effort into a boat I wasn't in love with.

But yeah, it was going to require a complete gutting; transom, stringer and deck replacement, new foam, etc...
 

bowman316

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Re: Is this boat too heavy?

Ok, So i drilled a hole, and sure enough the foam was really saturated in water. I then took up a small section of floor, and found out that there are no wooden stringers, just fiberglass beams running down the length of the boat, with cross members going perpendicular.

These beams have more floataion foam on the inside of them.

I just left that foam in there.

I cut open the whole back 4 feet of floor, but left the rest, for now, as it was not quite as wet up there.

So I am going to just put plywood over the section, and glue it down with liguid nails, or fiberglass resin.

Flotation foam is $100 bucks for 2 cubic feet. Screw that.

I am going to add one wood cross member for added support.

I will not fiberglass the top of the plywood, just paint it i guess.

I took a good 100- 150 lbs of crap out of there.
 

rolmops

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Re: Is this boat too heavy?

Ok, So i drilled a hole, and sure enough the foam was really saturated in water. I then took up a small section of floor, and found out that there are no wooden stringers, just fiberglass beams running down the length of the boat, with cross members going perpendicular.

These beams have more floataion foam on the inside of them.

I just left that foam in there.

I cut open the whole back 4 feet of floor, but left the rest, for now, as it was not quite as wet up there.

So I am going to just put plywood over the section, and glue it down with liguid nails, or fiberglass resin.

Flotation foam is $100 bucks for 2 cubic feet. Screw that.

I am going to add one wood cross member for added support.

I will not fiberglass the top of the plywood, just paint it i guess.

I took a good 100- 150 lbs of crap out of there.

I understand your feelings about spending $100 on flotation foam.But it is there to save your life in case things go very wrong.
Besides,it is very questionable that a life insurance will pay out a single penny to your loved ones if you drown and they find out that the flotation foam in your boat was removed.
 

bowman316

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Re: Is this boat too heavy?

yea, it may save yor life, but if the boat sinks, it sinks, and you have life jackets.

I don't really go too far from shore anyway, so If she sinks, I could swim to shore if i had to, or get rescued before i froze to death.

But i may put some old, dry foam in there, or olf life jackets or something like that.

Still, more than half of the foam is in there.
 

a70eliminator

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Sep 9, 2007
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Re: Is this boat too heavy?

This is true, it's not too often your boat capsizes, usually it's a mechanical problem that happens, in all my years of boating never have I nor any of my friends or family capsized a boat, it's usually big news when it does happen.
Although you have to determine if the foam is a structural part of the hull, some hulls have a thin fiberglass outer shell and the foam is what makes it strong, others have a strong thick enough shell that it can survive a beating without the foam filled voids.
 

bowman316

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Re: Is this boat too heavy?

This is pretty thick fiberglass, and the foam was not 100% filling to void, there was still some empty space, but not much.


I think gluing the plywood, with resin, to the strigers, will provide enough additional support. They also had some srews holding down the old plywood, driven into the stingers.

But is sealing the top of the floor with glass a requirement? I was just going to fill the gaps on the edges with calk or great stuff, and put some paint on top of the wood, with sand in the paint for grip.

I was also considering astro turf, but i think that holds too much water.
 

rockyrude

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Re: Is this boat too heavy?

All of the things you want to do are short term fixes. Those fiberglass beams are the stringers and they most probably have wood inside of them to give them their shape are most probably rotten seriously affecting the strength of the hull.
 

npd4432

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Apr 18, 2006
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Re: Is this boat too heavy?

All of the things you want to do are short term fixes. Those fiberglass beams are the stringers and they most probably have wood inside of them to give them their shape are most probably rotten seriously affecting the strength of the hull.

Rocky is most likely correct the wood on the stringers is incapsulated in the fiberglass, cut a piece of the fiberglass away to see if there is wood inside of them. When I did a floor that had the same problem I just "sistered" 2 2 x 6's after removing the rotted wood, worked pretty good for what I needed.
 

rebars1

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Re: Is this boat too heavy?

Check this place for much better foam prices, along with a choice of densities.

Look in the urethane foam section.

www.uscomposites.com
 

bowman316

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Re: Is this boat too heavy?

I am pretty sure that there is not wood under the fiberglass stringers, just more foam. I could feel under there in the back, and it did not feel like wood.

I might drill a small hole just to make sure thou.

I have never felt like the boat is structurally weak, it feels solid.
 

bowman316

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Re: Is this boat too heavy?

Update:

So there is wet foam under the stringers, And i just left it in there. I figure it will almost act like a keel, the prevent the boat from capsizing.

I pulled out all of the wet foam that was not under the stringers, and I put a 2 X 4 across the end of the floor (where the bilge area is, where the floor drops down). I glassed this in first, so i would have something to screw the new floor into. Then I put resin on the underside of the plywood, and put resin on the stringers. then I laid the board down, and screwed it into the 2X4 and the stringers. I put some weight on the floor while it was drying too.

Then I filled the gaps between the new and old floor with Bond-0 putty. Just yeasterday I sanded the whole floor of my boat, to remove carpet, and sand down the bond-o. I used a disc that you put into a drill to sand. Was pretty fast, worked very well. Beats changing sand paper in the sander ever 5 mins.


So now all I have to do is paint the floor, and put sand in the paint for grip.
 

superwooter

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Oct 12, 2009
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Re: Is this boat too heavy?

i hope this is proper forum etiquette, but i'd like to bump this thread back to the top and try to get some additional details on the core sample. please feel free to let me know if i should have posed my question in a new thread or any other way.

does anyone have pictures of this procedure? i am pretty sure i understand what tashasdaddy is saying to do, but i'm hesitant to cut a hole in the boat since i've never done this or seen it done. guess i'm a visual learner!

thanks for the help.
 

ezmobee

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Mar 26, 2007
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23,767
Re: Is this boat too heavy?

Welcome to iboats superwooter. We do prefer if you start your own threads for your questions. Down in the restoration section would be the best place for this one. Here's a thread with some of the info you're looking for http://forums.iboats.com/showthread.php?t=310508 Good luck!
 
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